bp: upgrade memcached engine config
bp: upgrade memcached engine config

Because ep-engine folks want to change static_config of ep-engine.

Change-Id: Ife0fc29a9ccfff3a5572b4c78dd6f313787118a7
Orig-Reviewed-on: http://review.couchbase.org/41265
Reviewed-on: http://review.couchbase.org/42979
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

mschoch/ns_server,membase/ns_server,nimishzynga/ns_server,ceejatec/ns_server,nimishzynga/ns_server,membase/ns_server,nimishzynga/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,mschoch/ns_server,membase/ns_server,ceejatec/ns_server,ceejatec/ns_server,membase/ns_server,membase/ns_server,ceejatec/ns_server,nimishzynga/ns_server,mschoch/ns_server,nimishzynga/ns_server